NO. IO COCKROACHES—ROTH AND WILLIS 97 
1912): From 1 to 30 worm larvae were found free in the abdomens 
of the cockroaches. Burma, Rangoon (Subramanian, 1927): In- 
numerable larvae were encysted in the body cavity. South Africa 
(Porter, 1930): The larvae were found in one cockroach. Madras 
(Sita, 1949). 
Experimental intermediate hosts—The following records appar- 
ently pertain to M. moniliformis: 
Blaberus fuscus, Netherlands (Brumpt and Urbain, 1938a): This 
species was refractory to infestation. Brumpt (1949) apparently re- 
fers this record to Blaberus atropos. 
Blatta orientalis and Leucophaea maderae, France (Brumpt and 
Urbain, 1938a): These cockroaches were easily infected. Argen- 
tina (Bacigalupo, 1928): Bacigalupo could not get the parasite to 
develop in B. orientalis. 
Blattella germanica, France (Brumpt and Urbain, 1938a). Argen- 
tina (Bacigalupo, 1928): Bacigalupo could not get the parasite to 
develop in this host. 
Periplaneta americana, Japan ( Yamaguti and Miyata, 1942). France 
(Brumpt, 1949). Madras (Sita, 1949). 
The following records apparently pertain to M. dubius: 
Blattella germanica, Japan (Yamaguti and Miyata, 1942). 
Periplaneta americana, Japan (Yamaguti and Miyata, 1942). 
U.S.A. (Chandler, 1941; Moore, 1946). 
Development in intermediate host—The eggs, when ingested by 
P. americana, hatched in the midgut within 24 to 48 hours. The larvae 
which were at first free in the lumen of the gut passed through the gut 
wall in the course of 10 to 12 days and dropped into the hemocoele or 
became embedded in fat tissue. The infective acanthella appeared 
about 7 to 8 weeks after infection. The encysted larvae remain dor- 
mant in the body cavity of the cockroach until it is eaten by a definitive 
host. (Moore, 1946.) Chandler (1949) found over 100 cystacanths 
of M. dubius in the body cavity of P. americana. 
Natural definitive hosts—Rodents such as rat, mouse, hamster, 
hedgehog, and squirrel; the parasite is sometimes found in man. 
(Burlingame and Chandler, 1941.) 
Experimental definitive host—Cotton rat (Sigmodon hispidus) 
(Moore, 1946). 
Development in definitive host—The cyst which contains the larva 
dissolves in the host’s stomach. The freed larvae pass into the small 
intestine and attach themselves to the intestinal wall. (Burlingame 
and Chandler, 1941 ; Moore, 1946.) 
